1. Field Of The Invention
The present invention relates generally to network management systems and, more particularly, to network management systems that manage objects arranged in a hierarchical structure.
2. Related Art
Network management is commonly defined as the process of controlling a communications network to maximize the efficiency and productivity of the network. A communications network may include a number of network entities or nodes, a number of interconnecting links and communication devices. A node may be, for example, a network node such as a personal computer, a network printer, file server or the like. An interconnecting link may be, for example, an Ethernet, Token-Ring or other type network link, while the associated communication devices may include routers, switches, bridges or their equivalents. As computer networks have grown in size, network management systems that facilitate the management of network entities, communication links and communication devices have become necessary tools for a network administrator.
A network management system typically includes a computer system or node on a communications network that executes what is generally referred to as a network management program. A network administrator uses such a network management program to primarily manage network entities. The network management program typically presents one or more maps of the network to the network administrator within a graphical user interface and includes a number of different tools for managing the network entities. An example of such a network management program is the ManageWise.RTM. network management program available from Novell, Incorporated, Orem, Utah. The ManageWise network management program provides centralized management of NetWare.RTM. servers and NetWare and IntranetWare.RTM. clients. The ManageWise network management program provides information concerning NetWare server configuration, memory allocation and processor usage, and manages devices such as servers and routers through the Simple Network Management Protocol (SNMP) and NetWare Core Protocol (NCP).TM., and client machines through the Desktop Management Task Force (DMTF) management interface (Desktop Management Interface (DMI)), (ManageWise, NetWare and IntranetWare are registered trademarks, and NetWare Core Protocol is a trademark of Novell, Incorporated). SNMP, NCP, and DMI are all well known in the art of network management.
The ManageWise network management program is generally used by a network administrator to specifically manage Novell networks. A Novell network includes NetWare and IntranetWare clients, NetWare servers, and other network nodes capable of communicating using the well-known NCP. NCP defines the services available to nodes which participate in the Novell network. Such services include file access, file locking, security, NetWare directory services, communication and connection, print services, queue management, and network management, among others. ManageWise may also be used to manage networks using SNMP as discussed below.
Network entities can be arranged in a hierarchical structure as objects to provide for more efficient management of the devices. For example, related objects may be grouped into a container object such as a folder. In the case of a large network, some network management programs allow a user to create folder or container objects representing sites, buildings, group, or other meaningful organizational entities. The user can then place an object representing the network entity in a location folder object to identify the location of the network entity. Other objects such as a relational database may inherently possess a hierarchical structure which can be reproduced in the network management program.
One database having such a hierarchical structure is the Novell Directory Services.RTM. (NDS) database by Novell Incorporated (Novell Directory Services is a registered trademark of Novell, Incorporated). The NDS provides a single logical view of all network services and resources in a Novell network. Also, the NDS database is globally distributed to multiple network nodes to provide clients access to network resources regardless of where the client is located. Specifically, the NDS database organizes objects of a hierarchical directory tree. Objects of the directory tree could include printers, users, servers and the like. As discussed above, folder objects may be created by a network administrator to organize objects of the directory tree. The hierarchical directory tree is used by the network administrator to add, delete, and otherwise manage objects in the network. In particular, the ManageWise network management program may be used by a network administrator to administer NDS objects.
The network administrator typically uses a graphical map to manually navigate through a hierarchical structure such as an NDS tree, to locate a problematic object; that is, an object that is behaving in such a manner to adversely impact network performance. Also, the network management program enters errors or traps in a log file, usually in the order of occurrence, for later review by the network administrator. Typically, the network management program makes entries in the log file when a trap is received by the network management program or when a statistical value in the network management program exceeds a threshold value. In conventional systems, and icon is often used to represent the network object. When an error is encountered, a characteristic of the icon, such as its color, is altered. The network administrator is then required to obtain additional information regarding the network object through the network management program to determine the status of the device and the source of the error. The network administrator must manually sift through the list of errors in the log file to locate the error that leads to the object that caused the errors. In this case, the network administrator must have prior knowledge of troubleshooting techniques for the network object at issue, and thus must know what data to observe from the network object. Also, because the network object interacts with other network objects, the network administrator must analyze a considerable quantity of data related to other network objects as well.
A concept of network object health is a recent development to simplify network management for the network administrator. Network health is a method of combining indicators into a single "health" value for a network object. An index representing the health of the Network Object is computed, usually having a numeric value having an associated color in which an icon representing the network object in the network management program is rendered. For a network object, multiple variables typically are monitored on a network management station. These variables have certain ranges, over which, the variables can have particular values. For example, for a network object such as a file server, the file server may have a indicator corresponding to the percent utilization of the processor that may take a value between zero and one hundred percent. For a particular type of network object, its overall health may be determined by a number of indicators such as percent utilization of the processor and other factors. By determining a health index for overall health, the amount of information that must be processed by the network administrator is reduced.
One conventional network management program utilizing such a health index is the Network Health network management program from Concord Communications. The Network Health network management program assigns fixed grades for each indicator value and assigns ranges for each grade. The grades for each indicator contributing to an overall health index are added together to determine the health index for a particular network object. For example, an excellent health grade would be given a grade of 0, a good health grade receives a grade of 2, a fair grade receives a grade of 4, and a poor grade receives a grade of 8. In the case of the determining the utilization of a link, a utilization range between 0 and 10% is given an excellent grade, between 10% and 20% a good grade, between 20 and 35% a fair grade and a utilization over 35% a poor grade. If, for example, a network object's utilization was 15%, the network object would receive a good grade for utilization, and thus receives a utilization health index of 2. The utilization health index may be combined with a number of other indices to determine an overall health index for a particular network object.
In the Network Health Network Management program, a network object is likely experiencing some type of problem when a health index has a value greater than a predetermined threshold value. Also, elements with a high health index may be problematic and should be investigated. However, a drawback to the Network Health network management program is that it may overestimate or underestimate problems for certain devices due to predetermined threshold values. If the defined range of values is underestimated, that is, threshold levels are set low relative to actual network conditions, numerous unnecessary error entries will be entered in the error log file. If overestimated, problems with network objects go undetected. Another drawback is that the network administrator is required to change the defined range of values for each variable used to calculate the health index to account for differences between various types of network objects. This requires the network manager to have prior knowledge of the type and scope of potential problems to adjust the levels of the health index. Typically, network administrators are not completely familiar with every network object, and thus do not have the requisite experience to properly adjust levels of the health index. As a result, the above overestimation and underestimation problems regularly occur.
Further, conventional network management programs that compute a health index determine a health index value that is not on a standard scale. That is, a health index for one object type may have index value ranges that are different than the same health index for another type of object. Thus, it becomes more difficult for a network administrator to identify objects experiencing a problem when comparisons between objects are not standardized.
Also, when a problem occurs in conventional network management programs, many related alarms are often raised concurrently, masking the source of the problem. An important alarm may be buried among less important alarms, and thus the more significant or important alarms may escape the attention of the network administrator. To avoid this from occurring, the network administrator must process a number of different network indicators to arrive at a problem resolution. As a result, a heavy burden is placed on the network administrator to skillfully and diligently process the network indicator information. Furthermore, this process is time consuming. However, the network administrator needs to obtain and process information quickly, as any delay may be problematic, such as when the problem causes a loss of network service.
The above drawbacks are further magnified due to the number of entities in large networks. In such large networks, many parameters must be observed concurrently. In an NDS tree, for example, there may be many layers of objects, and thus it is inefficient for a network administrator to traverse the NDS tree structure to locate a particular problem. Also, for complex problems involving multiple objects in the NDS tree, a network administrator must look at different indicators concurrently to determine the overall problem.
What is needed, therefore, is a network management system that allows a network manager to find problems quickly without prior knowledge of the problem. In addition, a network management system that provides a network administrator with accurate information of the source of a problem object would be beneficial. Such a network management program should be able to manage a large network having numerous network objects.